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#include <stddef.h>
#include <stdint.h>
#include "isr_vector.h"
void on_reset(void);
void __attribute__((weak, interrupt, __section__(".isr_vector.routines")))
default_irq_handler(void)
{
return;
}
#define WEAK_IRQ(irq) \
void __attribute__(( \
weak, alias("default_irq_handler"), __section__(".isr_vector.routines"))) \
irq(void)
WEAK_IRQ(irq_on_reset);
WEAK_IRQ(irq_on_nmi);
WEAK_IRQ(irq_on_exc);
WEAK_IRQ(irq_on_systick);
WEAK_IRQ(irq_on_swi);
WEAK_IRQ(irq_on_tmr0);
WEAK_IRQ(irq_on_gpio_a);
WEAK_IRQ(irq_on_gpio_b);
WEAK_IRQ(irq_on_spi0);
WEAK_IRQ(irq_on_blel);
WEAK_IRQ(irq_on_bleb);
WEAK_IRQ(irq_on_usb);
WEAK_IRQ(irq_on_tmr1);
WEAK_IRQ(irq_on_tmr2);
WEAK_IRQ(irq_on_uart0);
WEAK_IRQ(irq_on_uart1);
WEAK_IRQ(irq_on_rtc);
WEAK_IRQ(irq_on_adc);
WEAK_IRQ(irq_on_pwmx);
WEAK_IRQ(irq_on_tmr3);
WEAK_IRQ(irq_on_uart2);
WEAK_IRQ(irq_on_uart3);
WEAK_IRQ(irq_on_wdog_bat);
// Memory-mapped address of the data values in flash.
extern uint32_t ISR_VECTOR_IN_FLASH;
// Where the data is located in sram.
extern uint32_t ISR_VECTOR_START;
extern uint32_t ISR_VECTOR_STOP;
// Memory-mapped address of the data values in flash.
extern uint32_t DATA_VALUES_IN_FLASH;
// Where the data is located in sram.
extern uint32_t DATA_SEGMENT_START;
extern uint32_t DATA_SEGMENT_STOP;
// Where 0-initialized data is in sram.
extern uint32_t BSS_START;
extern uint32_t BSS_STOP;
static inline void set_mtvec(void* vector_table)
{
uint32_t mtvec = (uint32_t) vector_table;
mtvec |= 1; // Set interrupt table mode to "VECTORED"
asm volatile("csrw mtvec, %0" : : "r"(mtvec));
}
/*
* Initialize the data segment and the bss segment.
*
* This function loads data in the .data section from flash and puts it in
* memory where it can be edited and initialized the BSS data to 0.
*/
void init_data_segments(void)
{
/* Copy the data from the flash to memory. */
uint32_t* src = &DATA_VALUES_IN_FLASH;
uint32_t* dest = &DATA_SEGMENT_START;
while (dest != &DATA_SEGMENT_STOP) {
*(dest++) = *(src++);
}
/* Copy the ISR vector to memory. This makes it possible to still recieve
* interrupts even when the flash is powered down. */
src = &ISR_VECTOR_IN_FLASH;
dest = &ISR_VECTOR_START;
while (dest != &ISR_VECTOR_STOP) {
*(dest++) = *(src++);
}
dest = &BSS_START;
while (dest != &BSS_STOP) {
*(dest++) = 0;
}
}
/*
* External reference to the main() function.
*/
extern void main(void);
/* Start function. Responsible for initializing the system and jumping to the
* main function. */
static __attribute((__section__(".sinit.1"))) void start(void)
{
/* Initialize the data segments. */
init_data_segments();
/* Set the mtvec to the isr_vector. */
set_mtvec(&isr_vector);
/* Jump to main */
main();
}
/*
* The reset callback.This has to be a naked function because the stack pointer
* may not be initialized!!.
*/
__attribute((naked, __section__(".sinit"))) void _begin(void)
{
// Set up the stack pointer to point to the end of SRAM.
asm volatile(
"li sp,0x20008000\n"
"addi sp,sp,-4\n"
"jalr %0\n"
"spin:\n"
"j spin\n"
:
: "r"(start));
}
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